Rotary speed of said output shafts must be properly increased or decreased corresponding to the cloth material, but in customary speed regulating devices, rotary speed of the output shafts has been varied by transferring the pivot part at one end of an eccentric rod, pivoted movably in a diametric direction of the input shaft, to a desirable radial distance, and fixing at that position; hence in the case of said regulation, such operation as loosening and retightening of fixing bolts etc. of the pivot part at one end of said rod must be performed. Accordingly this regulating operation has been a troublesome matter and inefficient operation, since the transmitting mechanism such as the eccentric rod is received ordinarily within a main body case.
In the illustrated and preferred embodiment of this invention, a rotatable adjustment member carries a worm meshed with a shaft-mounted worm wheel, and a linkage connects the worm wheel shaft, the end of an eccentric rod, and the operating member of a unidirectional clutch, such that the rotary speed of output shafts carrying the cloth-pulling rollers can be regulated precisely during operation merely by turning the adjustment member.